1. Field of the Invention
The present invention relates to an article transfer apparatus mounted, for example, to a lift of a stacker crane in an automated warehouse.
2. Prior Art
Heretofore, as this type of an article transfer apparatus there has been known one wherein a slide fork is mounted to a lift (article carrier) so as to be movable in a front-to-back direction.
The said slide fork can perform such operations as protruding an article downward, lifting the article with ascent of the lift and retraction to the lift side, and thereby take in the article onto the lift. Further, by operations reverse to those operations, the slide fork can take down the article onto an article storage rack.
The above conventional article transfer apparatus has the following drawbacks.
Firstly, at the time of transferring or receiving an article to or from an article storage rack, the lift must be moved up or down in a projected state of the slide fork, so it is necessary that a space for vertical movement of the slide fork be provided between the article stored on the article storage rack and an overlying article storage rack. Since this space is a dead space, the article storage efficiency is reduced to an extent corresponding to the spaces provided between adjacent article storage racks.
Secondly, since each article storage rack has so far been required to have a clearance for passage of the slide fork therethrough, the conventional article transfer apparatus cannot be used for an article storage rack formed by a single plate.